[flang-commits] [flang] [flang] Fix constant subscript operations (PR #68352)

[Leandro Lupori via flang-commits]

luporl wrote:

This PR fixes part of the problem of https://github.com/llvm/llvm-project/issues/63770 (aborting when trying to reshape constant arrays where lower_bound + extent > INT64_MAX).

https://github.com/llvm/llvm-project/pull/68352